Calix[4]pyrrole‐Grafted Gold Nanoparticles as a Turn‐On Fluorescence Sensor for Noxious Fungicide Dimoxystrobin and Their Anti‐Cancer Activity against the KB‐3‐1 Cell Line.

A rapid and easy approach for producing very stable gold nanoparticles has been discovered. Calix[4]pyrrole tetrahydrazide (CPTAH) was utilized effectively in the synthesis of gold nanoparticles as a reducing and stabilizing agent. These functionalized AuNPs were characterized by Surface Plasmon Resonance, Transmission Electron Microscopy, Selected Area Electron Diffraction, and Energy Dispersive X‐ray techniques. CPTAH‐AuNPs possessed a particle size of 11±2 nm and are highly stable at pH 7.0 for more than 150 days. The selectivity and sensitivity of CPTAH‐AuNPs as a fungicide sensor was assessed for Metalaxyl, Mancozeb, Tebuconazole, Tricyclozole, Dimoxystrobin, Kresoxim‐methyl, and Carbendazim, amongst which Dimoxystrobin (DMX) was sensed exclusively with naked eyes by means of aggregation of CPTAH‐AuNPs with a detection limit of the order of 5 ppm using "Turn‐on" fluorescence enhancement. Additionally, the CPTAH‐AuNPs were found to be effective cytotoxic agent against the human cervix cancer cell line KB‐3‐1 with IC50 value of 64.63 μg/mL which admits the employability of CPTAH‐AuNPs in the study of development of anti‐cancer drug. [ABSTRACT FROM AUTHOR]